Scholarlink

<p>Carbon dots (CDs) have attracted widespread attention as versatile fluorescent nanomaterials. However, most existing CD-based sensors rely on a “turn-off” mechanism, which is susceptible to false positives, and the application of biomass-derived CDs for specific “turn-on” fluorescence responses to organic solvents remains rare. In this work, we synthesize fluorescent CDs from waste dragon fruit peel via a one-step hydrothermal carbonization (HTC) method using only water as the reaction medium (no external dopants). The resulting dragon fruit peel-derived carbon dots (DFCDs) exhibit a uniform quasi-spherical morphology with an average transmission electron microscopy (TEM) size of 12.65&#xa0;nm. Dynamic light scattering (DLS) measurements show hydrodynamic diameters of 18.2&#xa0;nm (polydispersity index (PDI) = 0.174) in water and 15.7&#xa0;nm (PDI = 0.136) in ethanol, along with a zeta potential of − 23.5 ± 0.36 mV, indicating excellent dispersibility. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) analyses collectively confirm the high purity of the DFCDs. Under optimal excitation at 370&#xa0;nm, the DFCDs dispersed in pure water show a fluorescence emission peak at 442&#xa0;nm with an intensity of 38 arbitrary units (a.u.). Remarkably, when dispersed in a water/ethanol mixture (1:7, v/v), the emission peak blue-shifts to 432&#xa0;nm with the fluorescence intensity dramatically increasing to 295 a.u. (a 7.8-fold enhancement). To the best of our knowledge, this is the first report of dragon fruit peel-derived carbon dots exhibiting a “turn-on” fluorescence response toward ethanol. The observed blue shift and dramatic enhancement are attributed to the reduced solvent polarity and the suppression of non-radiative decay pathways (disruption of the hydrogen-bonding network and passivation of surface defects). These results demonstrate that the environmentally friendly DFCDs possess excellent optical properties and hold great promise for constructing high-sensitivity “turn-on” ethanol-responsive materials, with potential applications in solvent discrimination, food safety monitoring, and bioanalysis.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Waste dragon fruit peel-derived carbon dots exhibit a turn-on fluorescence response to ethanol

  • 期刊论文

  • 发表日期：

    2026年6月15日

查看全文
  • Xueyuan Li,
  • Cong Chen,
  • Xinyao Yang,
  • Dean Fang

摘要

Carbon dots (CDs) have attracted widespread attention as versatile fluorescent nanomaterials. However, most existing CD-based sensors rely on a “turn-off” mechanism, which is susceptible to false positives, and the application of biomass-derived CDs for specific “turn-on” fluorescence responses to organic solvents remains rare. In this work, we synthesize fluorescent CDs from waste dragon fruit peel via a one-step hydrothermal carbonization (HTC) method using only water as the reaction medium (no external dopants). The resulting dragon fruit peel-derived carbon dots (DFCDs) exhibit a uniform quasi-spherical morphology with an average transmission electron microscopy (TEM) size of 12.65 nm. Dynamic light scattering (DLS) measurements show hydrodynamic diameters of 18.2 nm (polydispersity index (PDI) = 0.174) in water and 15.7 nm (PDI = 0.136) in ethanol, along with a zeta potential of − 23.5 ± 0.36 mV, indicating excellent dispersibility. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) analyses collectively confirm the high purity of the DFCDs. Under optimal excitation at 370 nm, the DFCDs dispersed in pure water show a fluorescence emission peak at 442 nm with an intensity of 38 arbitrary units (a.u.). Remarkably, when dispersed in a water/ethanol mixture (1:7, v/v), the emission peak blue-shifts to 432 nm with the fluorescence intensity dramatically increasing to 295 a.u. (a 7.8-fold enhancement). To the best of our knowledge, this is the first report of dragon fruit peel-derived carbon dots exhibiting a “turn-on” fluorescence response toward ethanol. The observed blue shift and dramatic enhancement are attributed to the reduced solvent polarity and the suppression of non-radiative decay pathways (disruption of the hydrogen-bonding network and passivation of surface defects). These results demonstrate that the environmentally friendly DFCDs possess excellent optical properties and hold great promise for constructing high-sensitivity “turn-on” ethanol-responsive materials, with potential applications in solvent discrimination, food safety monitoring, and bioanalysis.